1. Field of the Invention
This invention relates to slide switches. More particularly, the invention relates to a slide switch having a case member, a slide member movable within a planar range of movement defined in the case member, a conducting device formed between the case member and the slide member, and an elastic member for holding the slide member in a neutral position in which the conducting device becomes non-conducting.
2. Description of the Related Art
One example of slide switches as noted above is disclosed in Japanese laying-open patent publication H10-302576. This slide switch has a slide member movable within a planar range of movement defined in a case member, a conducting device formed between the case member and the slide member, and an elastic member for holding the slide member in a neutral position in which the conducting device becomes non-conducting. The conducting device comprises four elongate armatures formed by a conductive plate to act also as an elastic member. These four elongate armatures are mounted in a rectangular hollow space formed between the case member and the slide member. A conductive plate is disposed in the bottom of the rectangular hollow space for allowing the four elongate armatures to be used commonly. Specifically, each elongate armature is supported at one end thereof by a coiner of the case member, while the armature in a position adjacent the other end acting as a movable contact is pressed against a part of the slide member. As the slide member is moved in the range of movement by a manual operating force, a movable contact touches a fixed contact formed on an inner wall of the case member.
However, the above prior art construction has a large number of parts since the elastic member for maintaining the slide member in the neutral position consists of four elongate members. Further, a process of assembling the switch must include a complex step of pushing the four small elastic elongate members, against the elasticity of the elongate members, and in a way to maintain their correct posture, into the narrow rectangular hollow space between the case member and the slide member. This poses a problem of hampering improved manufacturing efficiency.
Another example of slide switches as noted above is disclosed in Japanese laying-open patent publication H7-235240. This switch has a case member, a slide member movable within a planar range of movement defined in the case member, a conducting device formed between the case member and the slide member, and an elastic member for holding the slide member in a neutral position. In this construction, a hollow, conductive, elastic ring mounted on a boss formed under the slide member acts as both the conducting device and the elastic member. A plurality of insulating projections erected on the bottom of the case member contact the outer surface of the elastic ring to hold the elastic ring in the neutral position. As the slide member is moved in the range of movement by a manual operating force, a peripheral part of the elastic ring is pushed out radially from between the insulating projections, to touch a fixed contact erected on the bottom of the case member.
This construction has a relatively small number of parts, and its assembling operation is considered relatively easy. However, it is technically difficult and involves increased cost to realize an elastic ring having sufficient conductivity, appropriate elasticity and physical durability, and the hollow structure as well.
An object of this invention is to provide a slide switch having a small number of parts, easy to assemble, and relatively inexpensive. Another object of this invention is to realize a slide switch, with a minimum number of parts, for constantly maintaining a slide member in an angular posture about an axis perpendicular to a plane of a range of movement.
A further object of this invention is to realize a slide switch, with a minimum number of parts, capable of detecting a manual operation applied to a slide member along Z-axis perpendicular to a plane of a range of movement in addition to a manual operation applied parallel to the plane of the range of movement.
The above objects are fulfilled, according to this invention defined in claim 1, by a slide switch comprising a case member, a slide member movable in a planar range of movement defined in the case member, a conducting device formed between the case member and the slide member, and an elastic member for holding the slide member in a neutral position where the conducting device is non-conductive, the elastic member being an integral unit having a holding portion engaged with the slide member, and projecting portions extending from the holding portion along the planar range of movement toward inner walls of the case member, wherein the conducting device includes contacts arranged on the inner walls of the case member, and conductors arranged on the holding portion of the elastic member, and the conductors of the elastic member are movable into contact with the contacts of the case member by an external force for moving the slide member away from the neutral position against a biasing force of the elastic member, and separable from the contacts by the biasing force of the elastic member when the external force is removed.
With the above characteristic construction, the slide switch according to this invention defined in claim 1 has the elastic member formed as an integral unit, and therefore the number of parts is reduced correspondingly. For the same reason, the elastic member may be assembled into the case member with ease. Further, the conducting device is realized by arranging the conductors on the holding portion of the elastic member. This allows the elastic member itself to be formed of an ordinary, inexpensive non-conductive elastomer, hence an advantage of a relatively low manufacturing cost.
The inner walls of the case member and outer surfaces of the slide member may have a common polygonal shape, each of the outer surfaces of the slide member being maintained parallel to an opposed one of the inner walls of the case member, absent the external force, by the biasing force of the elastic member.
With this construction, where, for example, the slide member is made movable from a neutral position in four directions, right and left and up and down, along the planar range of movement to realize four types of switching operation corresponding to the four directions, the slide member is positioned to have the conductors contact the predetermined contacts by virtue of contact between a side wall of the case member and a side wall of the slide member. This is achieved not only when the slide member is operated in the four directions, right and left and up and down, but also when the slide member is operated in a direction between two adjacent directions of the four directions. This assures a reliable switching operation and an agreeable operational feeling.
The inner walls of the case member and the holding portion of the elastic member may form squares as seen in a direction perpendicular to the planar range of movement, the projecting portions of the elastic member extending from respective corners of the square of the holding portion toward respective corners defined by the inner walls of the case member, the contacts may be formed on the four inner walls of the case member, respectively, and the conductors may be formed on the four sides of the holding portion of the elastic member, respectively.
This construction enables a light and swift switching operation since the conductors formed on the holding portion of the elastic member can contact the contacts formed on the inner walls of the case member substantially only by means of deformation of the projecting portions having a small sectional area. Further, the elastic member is prevented from inadvertently rotating inside the case member by engagement between extreme ends of the projecting portions and respective corners defined by the inner walls of the case member. This effectively avoids erroneous switching operations.
The case member may include support portions formed in the respective corners thereof for supporting the projecting portions of the elastic member to maintain the holding portion in a state spaced from a bottom surface of the case member.
This construction provides little chance of friction between the holding portion occupying a central region of the elastic member and the bottom surface of the case member, thereby enabling a light and swift switching operation. At the same time, this construction assures a smooth return to the neutral position of the slide member.
The elastic member includes bend points elastically yieldable even to a slight external force.
This construction furthers the light and swift switching operation.
Each of the projecting portions of the elastic member may have a pair of plate-like members separated by a slit extending radially outwardly from the holding portion, and joined together at extreme ends thereof.
With this construction, a movement of the slide member necessary to execute a single switching operation involves a deformation of only one side of certain projecting portion separated by the slit. Consequently, an external force required to move the slide member is halved, to realize a still lighter switching operation. Further, with this construction, the slide member is movable toward the corners in the case member while forcing its way into the slits. This feature enables two types of switching corresponding to two adjacent directions among the four, right and left and up and down directions.
In the construction noted above, each of the projecting portions may have, formed at an extreme end thereof, a bend point elastically yieldable even to a slight external force.
With this construction, a single switching operation and a simultaneous operation of two types of switching may be carried out with a lighter touch.
In another aspect of the invention, a slide switch, as set forth in claim 8, comprises a case member, a slide member movable in a planar range of movement defined in the case member, a conducting device formed between the case member and the slide member, an elastic member for holding the slide member in a neutral position where the conducting device is non-conductive, the elastic member having a holding portion engaged with the slide member, and projecting portions extending from the holding portion along the planar range of movement toward inner walls of the case member, and a guide mechanism for maintaining the slide member in a fixed angular posture about an axis perpendicular to the planar range of movement regardless of movement of the slide member caused by the external force, wherein the conducting device includes contacts arranged on the inner walls of the case member, and conductors arranged on the holding portion of the elastic member, and the conductors of the elastic member are movable into contact with the contacts of the case member by an external force for moving the slide member away from the neutral position against a biasing force of the elastic member, and separable from the contacts by the biasing force of the elastic member when the external force is removed.
With the above construction, the slide switch according to this invention defined in claim 8, the conducting device is realized by arranging the conductors on the holding portion of the elastic member. This allows the elastic member itself to be formed of an ordinary, inexpensive non-conductive elastomer, hence an advantage of a relatively low manufacturing cost. Further, the guide mechanism acts to maintain the slide member constantly in a fixed angular posture about the axis perpendicular to the planar range of movement. Thus, the elastic member is prevented from inadvertently rotating. Where a control member is disposed outside the case member for receiving a manual operating force directly, and transmitting this force to the slide member, the control member may have indications marked thereon to signify switching directions. Such a switch will perform excellent functions in a satisfactory manner.
In a further aspect of the invention, a slide switch, as set forth in claim 11, comprises a case member, a slide member movable in a planar range of movement defined in the case member, a conducting device formed between the case member and the slide member, an elastic member for holding the slide member in a neutral position where the conducting device is non-conductive, the elastic member having a holding portion engaged with the slide member, and projecting portions extending from the holding portion along the planar range of movement toward inner walls of the case member, and an auxiliary conducting device electrically switchable on and off by an external force applied to the slide member and acting along a Z-axis perpendicular to the planar range of movement, wherein the conducting device includes contacts arranged on the inner walls of the case member, and conductors arranged on the holding portion of the elastic member, and the conductors of the elastic member are movable into contact with the contacts of the case member by the external force for moving the slide member away from the neutral position against a biasing force of the elastic member, and separable from the contacts by the biasing force of the elastic member when the external force is removed.
With the above construction, the slide switch according to this invention defined in claim 11 is capable of detecting a manual operation applied to the slide member along Z-axis perpendicular to the planar range of movement as well as a manual operation applied parallel to the planar range of movement. This slide switch is realized while maintaining a minimum number of parts.
To realize the above construction, the slide switch may, specifically, further comprise an auxiliary elastic member elastically deformable by the external force acting along the Z-axis, wherein the auxiliary conducting device includes a fixed contact formed on a bottom surface of the case member, and a movable contact formed on the auxiliary elastic member for contacting the fixed contact in response to the external force along the Z-axis, and separable from the fixed contact upon removal of the external force acting along the Z-axis.
This construction detects a switching operation only when an operating force is applied to the slide member along Z-axis to elastically deform the auxiliary elastic member. While such an operating force is removed, the contact and movable contact remain separated by the action of the auxiliary elastic member.
The auxiliary elastic member may comprise a dome-shaped member having a concave side opposed to the surface of the case member, and a convex side opposed to the slide member, at least the concave side being formed of a conductive material acting as the movable contact.
With this construction, since the movable contact is formed on the convex side of the dome-shaped member opposed to the slide member, even where the slide member is slidable in contact with the convex side of the dome-shaped member, for example, resistance to the slide member within the planar range of movement may be equalized regardless of the direction of movement.
Further, even when a manual operating force is applied along Z-axis to a position slightly displaced from the center of the dome-shaped member, the central position of the dome-shaped member is elastically deformed to produce a conducting state. As a result, a simultaneous detection may be made of a switch-on state based an operation of the slide member in the planar range of movement, and a switch-on state based an operation of the slide member along Z-axis.
The slide switch may further comprise a control member supported outside the case member for receiving a manual operating force, the control member and the slide member being connected to each other whereby the manual operating force received by the control member is transmitted to the slide member.
With this construction in which the control member connected to the slide member as noted above, when the control member is operated in a sliding direction, the elastic member is deformed to enable an electrical detection of this operation. When the control member operated in the direction of depression, the auxiliary elastic member is deformed to enable an electrical detection of the operation along Z-axis. As a result, while allowing a smooth operation of the control member disposed outside the case member, a direction of operation may be electrically detected reliably.
The slide switch may further comprise a guide mechanism for maintaining the slide member in a fixed angular posture about an axis perpendicular to the planar range of movement regardless of movement of the slide member caused by the external force, wherein the guide mechanism includes an intermediate slide member disposed between the slide member and a lid covering an upper surface of the case member; and a guide member disposed between the slide member and the auxiliary elastic member; a first guide being formed between the slide member and the intermediate slide member for guiding the intermediate slide member to move along an X-axis relative to the lid, and a second guide being formed between the lid and the intermediate slide member for guiding the slide member to move along an a Y-axis intersecting the X-axis relative to the intermediate slide member; the guide member supporting the slide member movable within the planar range of movement, and deformable along a Z-axis perpendicular to the planar range of movement.
With this construction, when the slide member is operated, the guide mechanism causes the slide member to make a parallel movement. This eliminates the inconvenience of the slide member inadvertently rotating within the planar range of movement. Moreover, the slide member is guided by the guide member to move smoothly within the planar range of movement. Even where a depressing force acts to displace the slide member along Z-axis, the guide member is deformed to allow movement of the slide member. As a result, where the slide member has a control member in the form of a keytop, for example, and the control member has indications marked thereon showing switching directions, there is no possibility of errors occurring with the directions indicated. A depressing operation may be carried out smoothly despite the provision of the guide mechanism.
Alternatively, the slide switch may further comprise a guide mechanism for maintaining the slide member in a fixed angular posture about an axis perpendicular to the planar range of movement regardless of movement of the slide member caused by the external force; wherein the guide mechanism includes an intermediate slide member disposed between the slide member and the auxiliary elastic member; and a guide member disposed between the intermediate slide member and the auxiliary elastic member; a first guide being formed between the guide member and the intermediate slide member for guiding the intermediate slide member to move along an X-axis relative to the case member, and a second guide being formed between the slide member and the intermediate slide member for guiding the slide member to move along an a Y-axis intersecting the X-axis relative to the intermediate slide member; the guide member supporting the slide member movable within the planar range of movement, and deformable along a Z-axis perpendicular to the planar range of movement.
With this construction, when the slide member is operated, the guide mechanism causes the slide member to make a parallel movement. This eliminates the inconvenience of the slide member inadvertently rotating within the planar range of movement. Moreover, the slide member is guided by the guide member to move smoothly within the planar range of movement. Even where a depressing force acts to displace the slide member along Z-axis, the guide member is deformed to allow movement of the slide member. As a result, where the slide member has a control member in the form of a keytop, for example, and the control member has indications marked thereon showing switching directions, there is no possibility of errors occurring with the directions indicated. A depressing operation may be carried out smoothly despite the provision of the guide mechanism.